I ran into this situation not long ago, as far as running all of your webservers off port 80, I dont think that is possible without creating sub domains of some sort (ex. test.me.com, test2.me.com, test3.me.com)
Here are some links to explain things better
http://www.experts-exchange.com/Web/Web_Servers/Q_21025503.html
http://forums.isaserver.org/m_2002045602/mpage_1/key_/tm.htm#2002045602
good luck